Sinners are those who have committed unforgivable sins and are given the mark of thorns after they die. Sin Eaters are those who take the sins and punishment of sinners so they will not go to Hell. Rukiko, a simple village girl, wants to protect Raika, the Fire of God and the treasure of her beloved village, from Gaii, a Sin Eater who wants the chance to become sinless again. After hearing how Gaii became a Sin Eater, however, Rukiko's feelings change, but Angel Musa, the servant of God who brought her mother to Heaven, tells her not to sympathize with Gaii, and that it is the will of God. Whom can Rukiko trust?